class_docstr: Dummy servicer for gRPC server to call on.
  
  This is a dummy class that just pass through when calling on any method.
  User defined servicer function will attempt to add the method on this class to the
  gRPC server, but our gRPC server will override the caller to call gRPCProxy.
code: def __getattr__(self, attr):
      # No-op pass through. Just need this to act as the callable.
      pass
  
file_path: ray/python/ray/serve/_private/grpc_util.py
imports: from typing import Sequence
  import grpc
  from grpc.aio._server import Server
label_desc: Use image node_id 1 for calling the DummyServicer obj's underlying member method code with example usage: obj.__getattr__(attr) without return types